By Andi Anderson
Chestnut trees are susceptible to black stem borer infestation, posing a threat to their health and productivity. Growers should remain vigilant and take proactive measures to monitor and protect their trees from this damaging pest.
Black stem borers target a variety of woody plant species, including chestnuts, especially smaller trees with trunk diameters less than 4 inches and those under stress. Female borers lay eggs in tunnels within tree trunks, impairing the tree's ability to transport water and nutrients.
As the weather warms up, overwintering adults become active, typically in late April or early May, especially after consecutive days of temperatures reaching 68 degrees Fahrenheit or higher. Monitoring efforts, such as ethanol baited traps, are crucial for detecting black stem borer activity. Traps should be deployed near wooded areas at a height of 1.6 feet and refreshed regularly.
Growers with vulnerable trees or positive trap catches should consider applying trunk sprays to prevent damage. Timing is key, as insecticide application should coincide with female borer flight in the spring before they colonize new trees. Pyrethroid insecticides have shown effectiveness in reducing infestations within a season.
Young trees near orchard perimeters, particularly those adjacent to woodlots, are at higher risk and require extra attention. While monitoring for adults can be challenging due to their small size, traps help determine the optimal timing for insecticide application.
Later in the season, removing and disposing of dead or dying trees is essential for preventing further infestations. Proper disposal of prunings and brush piles is also necessary to eliminate potential habitats for overwintering adults.
By implementing proactive monitoring and prevention strategies, growers can safeguard their chestnut trees from the detrimental effects of black stem borer infestation, ensuring their health and productivity for years to come.
Photo Credit: pexels-mayukh-karmakar
Categories: Michigan, Crops